Demodulation reference signal (DMRS) for overlapped uplink (UL) and downlink (DL) DMRS resources

Abstract

A method of wireless communication by a user equipment (UE) includes receiving, from a base station, a downlink demodulation reference signal (DMRS) generated from a downlink DMRS configuration. The method also includes transmitting, to the base station, an uplink DMRS generated from an uplink DMRS configuration. A value of one or more parameter(s) of the uplink DMRS configuration differs from a value of the parameter(s) of the downlink DMRS configuration. A method of wireless communication by a base station includes transmitting, to a user equipment (UE), a downlink demodulation reference signal (DMRS) generated from a downlink DMRS configuration. The method also includes receiving, from the UE, an uplink DMRS generated from an uplink DMRS configuration. A value of one or more parameter(s) of the uplink DMRS configuration differs from a second value of the parameter(s) of the downlink DMRS configuration.

What is claimed is: 
     
       1. A method of wireless communication by a user equipment (UE), comprising:
 receiving, from a base station, a downlink demodulation reference signal (DMRS) configuration for a downlink DMRS scrambling ID and a downlink DMRS orthogonal cover code (OCC); 
 determining an uplink DMRS scrambling ID based on the downlink DMRS scrambling ID and determining an uplink DMRS OCC based on the downlink DMRS OCC; 
 receiving, from the base station, a downlink DMRS generated from the downlink DMRS configuration; and 
 transmitting, to the base station, an uplink DMRS generated from an uplink DMRS configuration, a first value of at least one parameter of the uplink DMRS configuration differing from a second value of the at least one parameter of the downlink DMRS configuration, wherein the at least one parameter of the downlink DMRS configuration includes at least one of the downlink DMRS scrambling identifier (ID), the downlink DMRS orthogonal cover code (OCC), a downlink DMRS transmission comb level, and a downlink DMRS transmission comb offset. 
 
     
     
       2. The method of  claim 1 , in which the transmitting occurs in response to the downlink DMRS at least partially overlapping with the uplink DMRS. 
     
     
       3. The method of  claim 1 , in which the determining of the uplink DMRS scrambling ID and the uplink DMRS OCC is based on a type of a downlink waveform and a type of an uplink waveform. 
     
     
       4. The method of  claim 1 , in which the determining of the uplink DMRS scrambling ID and the uplink DMRS OCC is based on a generated sequence on a cyclic prefix orthogonal frequency division multiplexed (CP-OFDM) waveform and a discrete Fourier transform (DFT) of the generated sequence on a single carrier (SC)-OFDM waveform. 
     
     
       5. The method of  claim 1 , further comprising determining the uplink DMRS configuration based on the downlink DMRS configuration. 
     
     
       6. The method of  claim 5 , in which the uplink DMRS configuration includes an uplink transmission comb level and uplink transmission comb offset, shifted by a shift amount, from a downlink transmission comb level and downlink transmission comb offset. 
     
     
       7. The method of  claim 6 , in which the shift amount is indicated by the base station. 
     
     
       8. The method of  claim 7 , further comprising receiving the shift amount via radio resource control (RRC) signaling, a media access control-control element (MAC-CE), and a downlink control information (DCI) message. 
     
     
       9. A method of wireless communication by a base station, comprising:
 transmitting, to a user equipment (UE), a downlink demodulation reference signal (DMRS) configuration for a downlink DMRS scrambling ID and a downlink DMRS orthogonal cover code (OCC) to enable determining of an uplink DMRS scrambling ID based on the downlink DMRS scrambling ID or determining of an uplink DMRS OCC based on the downlink DMRS OCC; 
 transmitting, to the user equipment (UE), a downlink demodulation reference signal (DMRS) generated from the downlink DMRS configuration; and 
 receiving, from the UE, an uplink DMRS generated from an uplink DMRS configuration, a first value of at least one parameter of the uplink DMRS configuration differing from a second value of the at least one parameter of the downlink DMRS configuration, wherein the at least one parameter of the downlink DMRS configuration includes at least one of the downlink DMRS scrambling identifier (ID), the downlink DMRS OCC, a downlink DMRS transmission comb level, and a downlink DMRS transmission comb offset. 
 
     
     
       10. The method of  claim 9 , in which the receiving occurs in response to the downlink DMRS at least partially overlapping with the uplink DMRS. 
     
     
       11. The method of  claim 9 , in which the uplink DMRS scrambling ID and the uplink DMRS OCC is based on a type of a downlink waveform and a type of an uplink waveform. 
     
     
       12. The method of  claim 9 , in which the uplink DMRS scrambling ID and the uplink DMRS OCC is based on a generated sequence on a cyclic prefix orthogonal frequency division multiplexed (CP-OFDM) waveform and a discrete Fourier transform (DFT) of the generated sequence on a single carrier (SC)-OFDM waveform. 
     
     
       13. The method of  claim 9 , in which the uplink DMRS configuration is based on the downlink DMRS configuration. 
     
     
       14. The method of  claim 13 , in which the uplink DMRS configuration includes an uplink transmission comb level and uplink transmission comb offset, shifted by a shift amount, from a downlink transmission comb level and downlink transmission comb offset. 
     
     
       15. The method of  claim 14 , further comprising indicating, to the UE, the shift amount. 
     
     
       16. The method of  claim 15 , further comprising transmitting the shift amount via radio resource control (RRC) signaling, a media access control-control element (MAC-CE), and a downlink control information (DCI) message. 
     
     
       17. An apparatus for wireless communication by a user equipment (UE), comprising:
 a memory; and 
 at least one processor coupled to the memory, the at least one processor configured: 
 to receive, from a base station, a downlink demodulation reference signal (DMRS) configuration for a downlink DMRS scrambling ID and a downlink DMRS orthogonal cover code (OCC); 
 to determine an uplink DMRS scrambling ID based on the downlink DMRS scrambling ID or determine an uplink DMRS OCC based on the downlink DMRSOCC has been replaced with the downlink DMRSOCC; 
 to receive, from the base station, a downlink DMRS generated from the downlink DMRS configuration; and 
 to transmit, to the base station, an uplink DMRS generated from an uplink DMRS configuration, a first value of at least one parameter of the uplink DMRS configuration differing from a second value of the at least one parameter of the downlink DMRS configuration, wherein the at least one parameter of the downlink DMRS configuration includes at least one of the downlink DMRS scrambling identifier (ID), the downlink DMRS orthogonal cover code (OCC), a downlink DMRS transmission comb level, and a downlink DMRS transmission comb offset. 
 
     
     
       18. The apparatus of  claim 17 , in which the at least one processor is configured to transmit occurs in response to the downlink DMRS at least partially overlapping with the uplink DMRS. 
     
     
       19. The apparatus of  claim 17 , in which the at least one processor is configured to determine the uplink DMRS scrambling ID and the uplink DMRS OCC based on a type of a downlink waveform and a type of an uplink waveform. 
     
     
       20. The apparatus of  claim 17 , in which the at least one processor is configured to determine the uplink DMRS scrambling ID and the uplink DMRS OCC based on a generated sequence on a cyclic prefix orthogonal frequency division multiplexed (CP-OFDM) waveform and a discrete Fourier transform (DFT) of the generated sequence on a single carrier (SC)-OFDM waveform. 
     
     
       21. The apparatus of  claim 17 , in which the at least one processor is further configured to determine the uplink DMRS configuration based on the downlink DMRS configuration. 
     
     
       22. The apparatus of  claim 21 , in which the uplink DMRS configuration includes an uplink transmission comb level and uplink transmission comb offset, shifted by a shift amount, from a downlink transmission comb level and downlink transmission comb offset. 
     
     
       23. The apparatus of  claim 22 , in which the shift amount is indicated by the base station. 
     
     
       24. The apparatus of  claim 23 , in which the at least one processor is further configured to receive the shift amount via radio resource control (RRC) signaling, a media access control-control element (MAC-CE), and a downlink control information (DCI) message.